Smart glasses may become a next mobile Internet data access platform, which, while providing users with new user experience, has some traditional Internet security issues. For example, traditional webpage administrators need to reject some access requests from machines. Different tests (for example, biometric authentication) for identifying an identity of an access initiator are thus developed, to ensure that a received request is from a human user rather than a machine or program. A common test is the Completely Automated Public Turing Test to Tell Computers and Humans Apart (CAPTCHA). Generally, the CAPTCHA displays a deformed display image that is difficult for a machine to identify, and requires a user to input a number or letter in the deformed display image, or answer a question in the deformed display image. However, with the continuous development of computer technologies, the rate of identification of the machine on the deformed display image is increasingly high, and the identification speed is increasingly fast; thus, security of the CAPTCHA needs to be further improved.